Watching our waterways

Some of the most turbid, salty and infrequently flowing rivers in the world, Australia's inland water systems are one of our most precious and challenged resources. But there are simple things we can all do to check the health of our waterways.

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Naturally turbid and saline, much of Australia's river systems, though vast, transport little water compared to rivers in the Northern Hemisphere.

Australia's longest river system, the Murray-Darling, stretches some 2154 km and is fed by catchments from 14% of Australia, yet in one year carries the equivalent water to that which flows through the Amazon River in Brazil in just one day.

Australian rainfall and stream flow is amongst the most variable in the world, and the southern half of the continent is under threat from drought and the impacts of climate change.

Water is a rare and precious resource, particularly in the drier parts of inland Australia, and already water trading in rural Australia and restrictions in urban areas have put freshwater to the forefront of social concerns.

Rivers and wetlands are the home of some of our most unique and iconic native species, from the platypus to the strange and ancient Queensland lungfish. Yabbies, barramundi and perch are well-known aquatic denizens, and Australian rivers are used extensively for recreation, including fishing, hunting, waterskiing and power boating.

Visitors and local luminaries

Although many of Australia's spectacular river systems and wetlands are in declining health, there's still a lot to see and enjoy.

Australia boasts 64 wetlands internationally listed for protection by the Ramsar Convention (a treaty dedicated to the 'wise use' of wetlands) and there are over 900 nationally listed wetlands that are important pockets of remnant habitat. According to the Australian government's Department of Environment and Water Resources, most people can find a nationally listed wetland within a 100 km drive of where they live,

One of the highlights of wetlands is migratory bird populations. These birds are often dependent on the persistence of wetlands and have come from as far as Siberia to escape the northern winter, spending spring and summer in Australia and New Zealand. Their presence or absence is a useful indicator of water health, and there are groups such as Birds Australia that specialise in counting these birds. While on the lookout for visitors, check out the local luminaries, resident birds from swans to moor hens, coots and ducks.

Fact file:

When: Inland stream flow is variable even within seasons. In southern Australia there is likely to be more water in spring and autumn, and in northern Australia flows are higher during late summer and autumn due to monsoonal rains.

Where: Australia wide. Check out The Australian RAMSAR wetlands database for nationally listed wetland areas nearby, or simply take a trip to your local creek to check on its health or just enjoy the area.

Other info: Threats to rivers and wetlands include reduced flows, salinity and weed, algae and pest invasions.

Platypuses are probably the most iconic Australian river dweller, with their odd, sensitive beaks, poisonous spurs and furry bodies. Looking a bit like brown furry logs, platypuses are hard to spot but live in surprisingly diverse habitats including farm dams and inner urban areas.

Platypuses require rivers and streams in good condition, with good water quality and flows. They are fussy home hunters and look for a particular type of river bank with the right soil structure to build their burrows, as well as particular invertebrates that live between the rocks on the river bed. River rocks also have to be a certain size to enable platypuses to shuffle them around with their beaks.

Turtles and frogs, although hard to spot, are excellent indicators of river health, and frog species in particular are commonly used for this purpose. Several states have organisations that pool information about frogs and encourage frog spotting reports.

Invertebrates are one of the most important and easily recognised indicators of river health. Yabbies, water snails and molluscs, worms, leeches, springtails and dragonflies are easily seen by the naked eye, and thrive where river health is good. The rates at which they disappear as well as the types that survive are used in scientific surveys to determine river health and there are books and web guides that can help you identify and look for key species.

River check up

Giving your local creek or wetland area a regular health check is one of the most exciting ways to familiarise yourself with the area. There are a series of key elements to looks for in assessing river and wetland health.

Water quality is monitored with a series of chemical and physical tests and may include checks for of salinity, temperature, turbidity, nutrients, phosphates, and dissolved oxygen.

Anyone from primary school students to adults and community groups can develop monitoring plans for their area in conjunction with Waterwatch or their local Catchment Management Authority, says NSW Waterwatch Coordinator Beryl Newman.

"Kids can do it, adults can do it, the whole community can do it," says Newman.

Newman stresses that visual assessment is just as important as other tests and can include looking out for riparian vegetation, bank stability and habitat assessments.

"If there's an issue with turbidity, or you can actually see banks collapsing, you can go to local government with that assessment and it can be a first step to try and get some local action," Newman says.

The Department of Environment and Water Resources says when assessing an area questions to ask yourself include is there sufficient water flowing through to maintain the animals and plants you would expect there? Can you see fish, frogs, birds, turtles, invertebrates and flora, such as trees and plants?

Salinity

The area of salt affected land in Western Australia is increasing at a rate of one football field per hour. Image: National Dryland Salinity Program. - From the River Landscapes website. [more pics]

Soil washed into rivers creates turbidity and often comes with an excess of nutrients. It can also increase the risk of one of Australia's largest water threats, salinity.

Saline water underground is normally balanced by deep rooted vegetation. When deep-rooted trees and shrubs are cut down, there is no evapotranspiration of water through the leaves and into the atmosphere. Irrigation may also add an influx of water leading to rising levels of saline groundwater.

According to the South Australian Department of Environment and Heritage, 30 to 50% of the Murray floodplain, from which Adelaide gets 90% of its drinking water, is expected to be affected by salinity by 2050.

In looking out for salinisation check for dead trees, water logged ground and salt scalding - a white crusts that forms where water has been.

Another threat to keep an eye out for is pollutants. These may be from isolated sources, such as sewerage discharge, or from diffuse inputs, such as agricultural sediments or stormwater from various sources. Further stresses on rivers and wetlands are the presence of weeds and invasive species, and land clearance in catchments for agricultural, industrial or urban use.

Tiny bugs and slime

Sludge and scum come in all different varieties, some of which are beneficial to water life and some are not. Algae forms part of many aquatic diets, but an excess of nutrients or a reduction in flow can cause algal blooms that suffocate aquatic inhabitants by blocking access to sunlight.

Blue green algae, which are actually an ancient life form called Cyanobacteria, are a natural part of Australia's inland streams but in excess can cause havoc. Blooms of the green-coloured cells can affect water quality even after the bacteria die (and turn blue), as their leaky cells exude toxins into the water and it can take months before sunlight and other bacteria clean up the damage.

For those with the technology to look more closely at the water, microscopic elements such as diatoms (microscopic, usually unicellular algae) and otoliths (fish ear bones) can provide information on habitat and climate change over time; such as temperature, salinity levels and oxygen.

But you don't need to go high-tech to learn about your river - a pair of binoculars and a bird guide, or a dip net and water bug book are a great starting point. Initially it can quite difficult to infer from your catch what's healthy or not, but you can quickly get a good idea of what characterizes your site.

Further info and credits

Special thanks to Bruce Gray from the Wetlands section of the Department of Environment and Water Resources, Lyn Smith from the Murray Darling Freshwater Research Centre and Beryl Newman from Waterwatch.